The invention relates to a battery cell. The invention furthermore relates to a battery module.
In most fields of use of electrical battery cells, apart from a comparatively small superposed ripple component, approximately direct current is drawn from the battery cells or fed into the battery cells.
An influence of a distributed inductance of a construction of the battery cell increases as the AC component of the current increases. Conventional cells have a metallic housing, a typical metal being aluminum. Situated therein are one or a plurality of cell windings, outgoing conductor films and forks, which are electrically conductively connected toward the outside to terminal poles of the cell. In order to avoid oxidation of the cell housing, the electrical potential thereof is put at positive, preferably by a direct electrical connection of the housing to the positive pole.
The prior art discloses battery systems having an integrated converter in which varying a phase voltage necessitates rapidly changing the current conduction through a battery module or past the battery module. In this case, e.g. in the automotive sector, the battery cells or modules of the battery systems mentioned are operated in relatively high frequency ranges up to the kilohertz range in order to drive an electric machine with the AC voltages generated.
An inductive component of the cell impedance acts toward the outside in relation to a power electronics system and, during the switching processes in combination with high currents, can generate high energy losses in the semiconductor switches used in the power electronics system. In certain unavoidable switching processes, avalanche breakdown (avalanche operation of the semiconductor switches) occurs in a manner driven by the electrical energy stored in the inductances.
DE 10 2010 041 028 A1 discloses an energy supply system having a controllable energy store serving for controlling and for supplying electrical energy to an n-phase electric machine where n≧1. In this case, the controllable energy store has n parallel energy supply branches having in each case at least two series-connected energy storage module comprising in each case at least one electrical energy storage cell with an assigned controllable coupling unit.